1. Field of the Invention
This invention relates to a mode changing mechanism for tape recording and/or reproducing apparatus, and particularly, but not exclusively, to a mode changing mechanism for a rotary-head-type digital audio tape player (R-DAT), or a video tape recorder (VTR), which has a tape loading device by which a tape is drawn out from a mounted tape cassette so as to enable the tape to run along a predetermined tape running path.
2. Description of the Prior Art
Generally, an apparatus, such as an R-DAT or a VTR, is equipped with a reel base driving member for selectively driving either of a pair of reel bases, a pinch-roller transferring member for transferring a pinch-roller to a selected one of a plurality of predetermined positions, a brake operating member which is operated to selectively arrest one or both of the reel bases, a back-tension exerting member for selectively exerting a back tension on one of the reel bases, a tape loading member for selectively loading or unloading a tape, etc., and an optional mode can be selected from among various kinds of modes, if the respective members are brought into pertinent positions thereof.
Such members usually are divided into several groups, and driven by a single motor and a plurality of drive mechanisms to connect the motor to the respective members in every group. However, even among the members belonging to the same group, there are generally certain differences in timings for moving the respective members, strokes or moving directions of the respective members, or the like, so that it is necessary to interpose cam means and speed changing means between the motor and each of the drive mechanisms, and further, to provide detecting means for detecting the positions of the respective members and the moved elements of the respective drive mechanisms. As a result, the apparatus becomes complicated in structure, the manufacturing cost rises, and it is difficult to miniaturize the apparatus.
Moreover, it becomes necessary to assemble the apparatus so that there is no phase shift between the drive mechanism and the members which have a closer relation with tape running, and such painstaking assembly requires much time. If there is a phase shift between the drive mechanism and the tape handling members, for example, the tape handling members do not correctly come to their predetermined pertinent positions when the apparatus is operated so as to select an optional mode, so that the apparatus will not be put in action.